GB1345918A - Cable control device - Google Patents

Abstract

1345918 Retracting aircraft undercarriages SOC NATIONALE INDUSTRIELLE AEROSPATIALE 19 April 1971 [7 April 1970] 26335/71 Heading B7G [Also in Division F2] An hydraulic selector D, Fig. 1, operable on an aircraft undercarriage, is actuated for lowering by a cable 4b from a pilot's control member A through a cable control device B and crank C. Cable 4a is the return cable. The cable control device includes a rotary member 3, Fig. 2, to which the cables are anchored at 5b, 5a, respectively. Cable 4b passes partly around a tensioning pulley 20 urged to the left by a tension spring 22 acting on a two-part lever 14 of which part 14b is integral with lever 17 (carrying pulley 20); lever part 14a carries a toothed detent 10, 11, which only just engages, in the rest position of Fig. 2, teeth on a ratchet wheel 9 secured to rotary member 3. In operation, when cable 4b is pulled to rotate member 3 counter-clockwise, the sideways force thereby exerted on pulley 20 pivots levers 17, 14, about 16 to raise detent 10 clear of ratchet wheel 9 to permit rotation. When cable 4a is pulled to rotate member 3 clockwise, the member rotates, during which rotation the teeth on ratchet wheel 9 successively escape from detent 10, which remains in contact with wheel 9. If the return cable 4a breaks in the absence of any positive actuating action at the pilot's station, cable 4b slackens, but the influence of spring 22 on lever 14 keeps tooth 11 of detent 10 engaged in the teeth of ratchet wheel 9, so rotation of member 3 is prevented and, in consequence, possibly-dangerous lowering of the undercarriage. A supplementary friction brake is applied at all times to the ratchet wheel 9 secured to member 3 (see Division F2).